For more information
Ernest A. Bates, M.D., Chairman and CEO
email: eabates@ashs.com

American Shared Hospital Services
Two Embarcadero Center, Suite 410
San Francisco, CA 94111

American Shared Hospital Services Shares Developments at Still River Systems

San Francisco, CA, March 5, 2009 -- AMERICAN SHARED HOSPITAL SERVICES (AMEX:AMS), a leading provider of turnkey technology solutions for advanced radiosurgical and radiation therapy services, today shared a recent announcement from Still River Systems, developer of the Monarch250, an affordable, precise and compact proton therapy system for cancer treatment in which AMS owns an equity interest, updating developments on Still River's proton therapy system:

Next Generation Proton Therapy System for Cancer Treatment Set for Release This Year

LITTLETON, Mass., Feb. 26, 2009 --  Still River Systems announced today the successful operation of the world's highest field, high energy cyclotron magnet. Still River's magnet is the key technical element for reducing the size and cost of the particle accelerator that will deliver proton therapy at a number of hospitals beginning with the first installation at Barnes Jewish Hospital in St. Louis, Missouri this fall.

"The last six months have been very exciting," said Marc Buntaine, CEO. "Still River has achieved all of the component milestones that bring us to system integration and delivery." Proton therapy, widely regarded as the next evolutionary step in the radiation treatment of cancer, has seen unprecedented interest from the radiation oncology and patient communities in recent years. However, the large size and high cost of existing proton therapy systems have made it difficult for the average hospital to add this powerful tool to their cancer fighting arsenal.

The heart of the Monarch250, a superconducting magnet developed in an industrial and academic partnership with the Massachusetts Institute of Technology, has now tested operational and stable at its full design current "This magnet sets a record for magnetic field strength used in a high energy cyclotron. The cyclotron built around this magnet will be the most compact source for proton therapy available today," said Dr. Kenneth Gall, founder and Chief Technology Officer.  "All of the Monarch250 sub‑systems are now in the final phases of manufacturing and will be ready to ship to our first customers for installation later this year."

Still River's Monarch250 proton therapy system, a unique and compact machine, was developed to provide proton therapy at a greatly reduced cost and size. In addition, Still River Systems has incorporated the latest advancements in radiation therapy patient management with its innovative accelerator technology, including a robotic couch for patient positioning, dedicated proton therapy treatment planning, cone beam CT imaging, and motion management. All of these clinical systems have been integrated within the Monarch250 platform.  "Our goal is to provide our customers with a fully integrated, turnkey proton therapy solution with the most advanced clinical systems for patient management," said Dr. Skip Rosenthal, Vice President of Clinical Systems. "Integrating these key radiation therapy technologies is critical to ease of use in a clinical setting."

Still River Systems first installation sites, Barnes Jewish Hospital in St. Louis, Missouri and Robert Wood Johnson University Hospital in New Jersey, have begun construction for the new facilities that will house the first Monarch250 systems in the United States.

Still River Systems, based in Littleton, Massachusetts, is dedicated to providing physicians and their patients' access to high quality, cost‑effective proton therapy solutions. Still River Systems is developing the Monarch250, an affordable, precise and compact proton therapy system for cancer treatment. This system has not yet been cleared by the FDA for commercial use in clinical therapy. For more information on Still River Systems and the Monarch250 Proton Therapy System, please call 978‑540‑1500 or visit www.StillRiverSystems.com.

About AMS
American Shared Hospital Services provides turnkey technology solutions for advanced radiosurgical and radiation therapy services.  AMS is the world leader in providing Gamma Knife radiosurgery equipment, a non-invasive treatment for malignant and benign brain tumors, vascular malformations and trigeminal neuralgia (facial pain).  The Company also offers the latest IGRT and IMRT systems, as well as its proprietary Operating Room for the 21st Century® concept.  Through its preferred stock investment in Still River Systems, AMS also plans to complement these services with the Monarch 250TM proton beam radiation therapy (PBRT) system, which has not yet been approved by the FDA.

Safe Harbor Statement
This press release may be deemed to contain certain forward-looking statements with respect to the financial condition, results of operations and future plans of American Shared Hospital Services, which involve risks and uncertainties including, but not limited to, the risks of the Gamma Knife and radiation therapy businesses, the risks of developing The Operating Room for the 21st Century program, and the risks of investing in a development-stage company, Still River Systems, Inc., without a proven product.  Further information on potential factors that could affect the financial condition, results of operations and future plans of American Shared Hospital Services is included in the filings of the Company with the Securities and Exchange Commission, including the Company's Annual Report on Form 10-K for the year ended December 31, 2007, the Quarterly Report on Form 10-Q for the quarters ended March 31, 2008, June 30, 2008 and September 30, 2008, and the definitive Proxy Statement for the Annual Meeting of Shareholders held on June 20, 2008.

Contacts:
American Shared Hospital Services
Ernest A. Bates, M.D., (415) 788-5300
Chairman and Chief Executive Officer
eabates@ashs.com

Berkman Associates
Neil Berkman, (310) 826-5051
President
info@berkmanassociates.com

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